(b) Magnified fifty times: When very young they are delicate, star-like, branching figures; later there gradually develops a denser, opaque center, with a delicate, ramifying peripheral zone.

Sugar-agar.-Stab: After twenty-four hours there is a small, whitish wart upon the surface, which gradually grows into a slightly elevated disk with a somewhat wrinkled surface and brownish-yellow color. The wrinkling, elevation, and extension of the growth increase for a long time; the periphery presents a delicate, flat, radially wrinkled border. In the stab there is only slight growth in the upper part. Upon ordinary agar the growth is more feeble and paler in color.

Bouillon Culture.-Delicate surface pellicle with white granules. The latter grow downward as tough masses (resembling drops of stearin), and then fall to the bottom, where a rich mass of the fungus gradually accumulates. The bouillon always remains perfectly clear.

Potato Culture.-At first a coarsely granular fillet, made up of snow-white nipples, and by degrees becoming wrinkled and brick-red. After about fourteen days a delicate, white, hairy covering develops at the periphery and gradually covers the entire red growth.

Spores. Nothing is known regarding the resistance of the short segments known as "spores."

Distribution.-Found by Eppinger on only one occasion in the lymph-glands, and especially in a brain abscess and in the cerebral and spinal meninges of a glass-grinder, where it apparently was the cause of the disease.

Pathogenic Effects. When introduced in various ways, it causes in animals (guinea-pigs, rabbits) a fatal disease resembling tuberculosis. (Pseudotuberculosis cladothrichica.) It has been shown by Lubarsch that it can form in animals colonies which are deceptively like actinomyces.

Actinomyces carneus. (Rossi Doria.) Gasperini. Streptothrix carnea Rossi Doria. Closely related to the Act. asteroides. However, gelatin and agar cultures show distinct air mycelium, which gives the gelatin culture a pink, and the agar culture from a flesh to a reddish

orange color. It is not pathogenic for animals. The actinomyces aurantiacus (Rossi Doria) Gasperini is similar.

Actinomyces maduræ. (Vincent.) Lehm. and Neum.

Streptothrix maduræ Vincent (A. P., 1894, 129).

There is great similarity to actinomycosis in the course of the disease known as "madura-foot, madura-boil, Dehli-boil" (first brawny, then nodular, usually perforating externally). It is a disease, affecting especially the feet and hands, which is native to India, but also occurs in northern Africa, Italy, etc. Our description is from Vincent. In the pus from the fistulæ there are found bodies (gray, yellow, black) similar to those of actinomycosis, which, according to Kanthack's illustrations, have the same structure as actinomyces granules.

The organisms are obligate aerobes, and grow excellently upon decoctions of potato, turnip, etc., which have not been neutralized, with the production of alkali. As the best solid nutrient medium, Vincent employed a decoction of hay or potato to which is added, for every 100 gm. of gelatin, 4 gm. of glycerin and 4 gm. of grape-sugar. Gelatin is not liquefied. Old gelatin cultures resemble a vaccine pustule, being dry, closely attached to the nutrient medium, somewhat depressed in the middle, whitish, the periphery red. Upon potatoes whitish-red prominences, which often present an air mycelium with conidia; also in other mycelium, spore-formation occurs. There is no musty odor. The spores die in three minutes at 85° and in five minutes at 75°. The cultures with no spores die at 60° in from three to five minutes. The threads and conidia stain readily with all the anilin dyes and by Gram's method. It is not pathogenic for animals (rabbits, guinea-pigs, mice, cats).

Actinomyces chromogenes. Gasperini.

(Plate 67.)

Synonyms.1-Streptothrix chromogena Gasperini, Oospora Metschnikovi Sauvageau and Radais,2 Streptothrix nigra Doria. Cladothrix dichotoma Macé, Günther

1 We describe a variety isolated by ourselves; the synonyms we have determined in part from comparison with the descriptions, in part from the cultures.

2 Sauvageau and Radias could not find spores in their Streptothrix Metschnikovii,

non Cohn. Cladothrix odorifera Rullmann (C. B. XVII, 884, and C. B. L. II, 701). 66 'Brauner Hesse."

Microscopic Appearance.-True branching threads, often with perceptible separation into longer and shorter rods (67, x). There is no motility, but Rullmann has seen motion in the youngest stages.

On the air threads (see below), by continuous transverse division, short roundish members are formed (true conidia), which very readily fall off, and, upon germination, form new branching mycelium.

Staining Properties. With all anilin dyes and by Gram's method.

Relation to Oxygen.-Grows better aerobically.

Requirements as Regards Temperature and Nutrient Media. Thrives upon all ordinary nutrient media at room and incubator temperature, more rapidly at the latter.

Gelatin Plate.-(a) Natural size: At first the colonies are brownish, round, slightly elevated, tough, dull, and begin first in the center, rarely at the periphery, to take on a whitish, chalky condition. Hereupon are formed concentric, wide, white rings; the drier (thinner) the nutrient medium, the more rapidly there occurs a more or less complete overgrowth of the colony, with white air hyphæ, and therewith a chalky appearance. The gelatin near the colony is colored dark brown and is slowly lique

fied, so that finally round, pea-sized, chalky crusts float in shallow cups (67, v and VI).

(b) Magnified sixty times: Very young colonies consist of a confused ball of threads; older ones appear but slightly transparent, with zones having wavy, jagged boundaries, all of which are darker in their peripheral portions. The edge of the colony is beset with delicate threads, like a fringe, which extend outward into the discolored gelatin (67, vII).

Gelatin Stab.-The surface growth is like that on the gelatin plate. Sometimes drops of fluid (no oil!) are seen upon the surface of the growth. The gelatin is very slowly liquefied from above downward. In the stab the short, radiating tufts of fibrils, which even at first develop, can be observed for a long time (67, 1).

Agar Plate.-(a) Natural size: As upon gelatin.

(b) Magnified sixty times: After about six days no structure is distinguishable in the dense colonies; they are dark and homogeneous and surrounded by distinct fringes (67, VIII).

Agar Stab.-Upon the surface the growth at first is rather moist, with a yellowish luster and elevated like the head of a nail; later it is drier, tough, and somewhat puffed. The agar is discolored brown. In the stab there are radiating, bristle-shaped branches (67, III and IV).

Agar Streak.-The growth spreads out only moderately, presents (after four to six days) a brownish color, and on the thinner parts of the agar a white, chalky, peripheral zone. In the course of time the whole becomes whitish and chalky. Upon the clear water of condensation there later forms a tough, brownish film, which also develops chalky, white air hyphæ, especially on the glass walls (67, 11). At other times a clumpy growth is present at the bottom of the water of condensation without any pellicle.

Bouillon Culture.—At first a delicate and later a dense pellicle. In grape-sugar bouillon there are thick, clumpy, radially arranged masses on the bottom. The bouillon

becomes brown.

Milk Culture.-Dense, yellowish-brown to cinnamoncolored layer on top. The milk is clarified and alkaline.

Potato Growth.-Growth quite rapid and luxuriant. As early as forty-eight hours in the incubator, a yellow, yellowish-brown, greenish-brown, or brown layer, 8 mm. wide, has formed. In our cultures the chalky appearing air hyphæ always began at the edge. The potato is later discolored intensely brown to black, and becomes strongly alkaline.

Chemical Activities.-There is produced a dark-brown pigment and an intense moldy odor upon all nutrient media. According to Rullmann, the earthy smell is most intense upon bread pap and other media composed of carbohydrates. There occurs a nitrogenous body, soluble in water and ether. The odor is said to be the same as arises from an unclean floor upon washing. Ammonia is abundantly formed. According to Rullmann, in symbiosis with fission-fungi it has considerable capacity for forming nitrate.

Distribution. (a) Outside the body: In Würzburg it is not uncommon in the air, soil, and water, and appears also otherwise distributed.

(b) In organism: We found it once in gastric contents. Special Methods for Demonstration and Cultivation.-Agar tion. Agar plates in incubator. Observe brown halo, chalky discoloration, odor.

Actinomyces chromogenes Gasperini ß alba. L. and N. Streptothrix Foersteri Gasperini (Cohn?), Streptothrix alba Rossi Doria, Streptothrix I and II Almquist, Oospora Guignardi Sauvageau and Radais, Actinomyces albus Gasperini, Oospora Doria Sauvageau and Radais.

1

According to Doria, it is especially frequent in Rome, but occurs also in Würzburg. It does not color the nutrient media. It forms a white cushion of circular form, and tends to produce abundant airspores. Gelatin is liquefied.

According to Gasperini, the cultures many times exhibit a sudden production of pigment, like the Actin. chromogenes. According to Rossi Doria, it also grows upon fucus (sea-weed) nutrient media with a dark discoloration of the nutrient medium. From what we have seen and learned from the literature, the only possible comprehension

1 The Cladothrix invulnerabilis Acosta y Grande Rossi (C. B. XIV, 14) appears closely related. It is said to bear heating for one-quarter hour to 120°. The cultures have an earthy odor.